Yii2-Integrity constraint violation – yii\db\IntegrityException - php

Question

Integrity constraint violation – yii\db\IntegrityException
SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`jts`.`employee`, CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`))
The SQL being executed was: INSERT INTO `employee` (`client_code`, `company_name`, `emp_email`, `emp_mobile`, `emp_first_name`, `emp_last_name`) VALUES ('12345678', 'PVPPCOE', 'saurabhkulkarni2010#hotmail.com', '[phone]', 'Saurabh', 'Kulkarni')
Error Info: Array
(
[0] => 23000
[1] => 1452
[2] => Cannot add or update a child row: a foreign key constraint fails (`jts`.`employee`, CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`))
)
I have three tables Client, Employee and create_client, out of which client and employee has two foreign keys.
This problem is showing when I try to insert data from create_client to employee which has exact same field.
What should I do so that I can insert two tables at one i.e create_client and employee
UPDATE-
Table Structure
1)client
CREATE TABLE IF NOT EXISTS `client` (
`id` int(11) NOT NULL,
`client_code` varchar(11) NOT NULL,
`company_name` varchar(45) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=29 DEFAULT CHARSET=utf8;
2)create_client
CREATE TABLE IF NOT EXISTS `create_client` (
`id` int(11) NOT NULL,
`client_code` varchar(11) NOT NULL,
`company_name` varchar(45) NOT NULL,
`emp_email` varchar(45) NOT NULL,
`emp_mobile` varchar(45) NOT NULL,
`emp_first_name` varchar(45) NOT NULL,
`emp_last_name` varchar(45) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=43 DEFAULT CHARSET=utf8;
3)employee
CREATE TABLE IF NOT EXISTS `employee` (
`id` int(11) NOT NULL,
`client_code` varchar(11) NOT NULL,
`company_name` varchar(45) NOT NULL,
`emp_email` varchar(45) NOT NULL,
`emp_mobile` varchar(45) NOT NULL,
`emp_first_name` varchar(45) NOT NULL,
`emp_last_name` varchar(45) NOT NULL
) ENGINE=InnoDB AUTO_INCREMENT=20 DEFAULT CHARSET=utf8;
This is my table structure, first user will create client that means first it will update create_client. Now if user wants he can add many employee under one client code now user will update employee table from Yii2 dynamic form widget.
For using this widget I have created one table call client this will store only client_code and company name remaining data will go in employee table e.g emp_mobile,emp_email, emp_first_name, emp_last_name.
Now this problem is pop up when user first enters data into create_client table.
everything is working between client and employee table user able to enter as many employee as it wants using Yii2 dynamic form Widget but not working for create_client

Answer 1

Apparently you also have a foreign key in the employee table referencing the client_code of the client table, so you can only use client_code values that already exist in the client table.
I don't know what the structure of the create_client table looks like and what its purpose is, but based on your info I assume that you should first insert the data in client, then in employee and finally in create_client, so that every foreign key's value exists in its respective table.
If this is not correct, please post your table structures and the data or queries that could be causing this.
Edit after your comment: I assume that your table structure looks like this:
CREATE TABLE `create_client` (
`client_code` INT UNSIGNED NOT NULL,
`company_name` VARCHAR(255) NOT NULL,
`emp_mobile` VARCHAR(255) NOT NULL,
`emp_email` VARCHAR(255) NOT NULL,
`emp_first_name` VARCHAR(255) NOT NULL,
`emp_last_name` VARCHAR(255) NOT NULL,
UNIQUE KEY `client_code` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
CREATE TABLE `client` (
`client_code` INT UNSIGNED NOT NULL AUTO_INCREMENT,
`company_name` VARCHAR(255) NOT NULL,
PRIMARY KEY `client_code` (`client_code`),
CONSTRAINT `client_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `create_client` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
CREATE TABLE `employee` (
`client_code` INT UNSIGNED NOT NULL,
`company_name` VARCHAR(255) NOT NULL,
`emp_mobile` VARCHAR(255) NOT NULL,
`emp_email` VARCHAR(255) NOT NULL,
`emp_first_name` VARCHAR(255) NOT NULL,
`emp_last_name` VARCHAR(255) NOT NULL,
KEY `client_code` (`client_code`),
CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
However, I would suggest to use client as the parent table and move the foreign key constraint to create_client, so that both employee and create_client have a foreign key of client. I would also like to normalise this and get rid of company_name in the child tables:
CREATE TABLE `client` (
`client_code` INT UNSIGNED NOT NULL AUTO_INCREMENT,
`company_name` VARCHAR(255) NOT NULL,
PRIMARY KEY `client_code` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
CREATE TABLE `create_client` (
`client_code` INT UNSIGNED NOT NULL,
`emp_mobile` VARCHAR(255) NOT NULL,
`emp_email` VARCHAR(255) NOT NULL,
`emp_first_name` VARCHAR(255) NOT NULL,
`emp_last_name` VARCHAR(255) NOT NULL,
UNIQUE KEY `client_code` (`client_code`),
CONSTRAINT `create_client_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
CREATE TABLE `employee` (
`client_code` INT UNSIGNED NOT NULL,
`emp_mobile` VARCHAR(255) NOT NULL,
`emp_email` VARCHAR(255) NOT NULL,
`emp_first_name` VARCHAR(255) NOT NULL,
`emp_last_name` VARCHAR(255) NOT NULL,
KEY `client_code` (`client_code`),
CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
The next improvement would be to use the employee table for both unique and non-unique client_code inserts. Instead of using 2 identical tables, apart from the unique key, you could do the unique validation in Yii instead of in MySQL. You can specify the table name in the tableName() method of the CreateClient model . This will remain:
CREATE TABLE `client` (
`client_code` INT UNSIGNED NOT NULL AUTO_INCREMENT,
`company_name` VARCHAR(255) NOT NULL,
PRIMARY KEY `client_code` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
CREATE TABLE `employee` (
`client_code` INT UNSIGNED NOT NULL,
`emp_mobile` VARCHAR(255) NOT NULL,
`emp_email` VARCHAR(255) NOT NULL,
`emp_first_name` VARCHAR(255) NOT NULL,
`emp_last_name` VARCHAR(255) NOT NULL,
KEY `client_code` (`client_code`),
CONSTRAINT `employee_ibfk_1` FOREIGN KEY (`client_code`) REFERENCES `client` (`client_code`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
This should allow you to use the dynamic form, with Client as the main model and Employee as the items model.

Answer 2

On Yii2 using IO Generator (Model) and MySQL I have found the following.
I have seen SET '' instead of SET NULL in update SQL statement(s) on field(s) with foreign key constraints that have caused a "Integrity constraint violation".
My "fix" is to add a default rule on the foreign key field in the model, like so:
public function rules()
{
return [
//
// your other rules
//
[['field_name_with_foreign_key'], 'default', 'value' => null],
];
}
Hope this helps someone.

Answer 3

remove all foreign key checks and simplify database.
the problem lies in your foreign key structure.
learn carefully about primary keys and foreign keys.
make new database again without foreign keys then check.